Cerium oxideCerium oxide (CeO2) is one of the most common and important rare earth metal oxides. Its high abundance, combined with excellent catalytic activity for a variety of reactions, makes cerium the element of choice for the automotive industry enabling the catalytic conversion of the exhaust system of automobiles.

Applications

Cerium oxide is used significantly by the glass industry as an efficient polishing agent for most glass compositions and also to prevent the decolorization of glass. These applications consume a significant portion of the cerium oxide products. Cerium oxide has been widely used as a promoter and an oxidation heterogeneous catalyst because of its unique redox properties and high oxygen storage capability. CeO2 has potential applications for UV blocks, polishing materials, the three-way catalysts (TWCs) and in solid oxide fuel cell (SOFC). In addition, supported CeO2 and CeO2-based mixed oxides are effective catalysts for the oxidation of different hydrocarbon and for the removal of organics from wastewater from different sources. These properties of the high mobility and storage capacity of oxygen within the lattice, the ease with which cerium changes between Ce3+ and Ce4+ states combined with the abundance of cerium on earth, make ceria a low-cost highly effective alternative to noble metal catalysts. Cerium oxide is used for cracking crude oil in refinery operations; Self-cleaning ovens utilize cerium oxide for its self-cleaning properties. Cerium oxide is being increasingly used to clean vehicle exhaust streams. Cerium compounds can be grafted onto cellulose, wool, starch, and cotton to initiate polarization of vinyl on their surfaces. This improves the mechanical strength, adds resistance to moisture and microorganism attack. These materials are then used in the manufacture of rain gear and similar products. The ability of cerium-doped glass to block out ultra violet light is utilized in the manufacturing of medical glassware and aerospace windows. It is also used to prevent polymers from darkening in sunlight and to suppress discoloration of television glass. It is applied to optical components to improve performance. High purity Ceria are also used in phosphors and dopant to crystal.

Synthesis of Cerium Oxide Nanotubes

Cerium oxide nanotubes are synthesized using a modified method developed byZhou and others. A sample of 0.5 g cerium(III) sulfate hydrate (Ce2(SO4)3• X H2O, is first dissolved into 40 mL of 10 M sodium hydroxide aqueous solution (NaOH (aq), solution. The solution is transferred to a 45 mL total volume Parr autoclave, and is allowed to react at 120 °C for 15 hours. The cooled sample is filtered using 0.8 μm membranes and rinsed with 3 aliquots of 50 mL water. After rinsing, the sample is placed in a convection oven at 50 °C for 1 hour. The samples are then gently powdered using a spatula and heated at 50 °C for an additional hour for this partial oxidation step. The resulting samples are mixed with 50 mL of water, and 50 mL of ~15% hydrogen peroxide, immediately followed by sonication for 30 minutes. Following sonication the samples are left in the H2O2 solution for an additional 60 minutes for their oxidative transformation into tubular structures. Lastly, the material is filtered using a 0.8 μm membrane, rinsed with three aliquots of water and dried in a convection oven at 50 °C.